For some years, Anish Kapoor, the India-born British artist, held the rights to use the then blackest pigment, called Vantablack, which absorbs 99.96 per cent of visible light. He still does, only Vantablack isn’t the blackest anymore. In 2019, engineers at the Massachusetts Institute of Technology created a blacker coating using carbon nanotubes, which can absorb 99.995 per cent of visible light.
What is this race to create ‘blacker’ stuff all about? Black coats are pretty useful in space telescopes, as they absorb unwanted cosmic glare. Of course, blackness also enhances thermal and electrical properties.
A testimony to the beauty of blackness stands in a vitrine in the New York Stock Exchange — a $2-million diamond painted black by MIT artist Diemut Strebe. A diamond is a highly reflective material, but here you look at this diamond, you look into a void.
Not to be outdone, ‘white’ is getting a lot of attention, too. While commercial white paints reflect 80-90 per cent of light, Xiulin Ruan of the Purdue University has recently created a white paint that reflects 98.1 per cent of sunlight — using barium sulfate, a compound used to whiten photo paper. Even if the paint takes in heat from other sources, it spews it back as infrared. Earlier, the ‘white’ record was held by a calcium carbonate-based paint, which reflected 95.5 per cent of sunlight. White paints help keep buildings cool, reducing the workload of air conditioners.